Steerable system for asphalt milling attachment

ABSTRACT

A steering mechanism and guidance system for a milling attachment device provides steering capability without impeding cutting depth control. The steering mechanism has at least one wheel that is rotated by an actuating mechanism such as an extending cylinder, synchronized actuators, or the like. The steering mechanism may be integrated with depth control by using a parallelogrammic structure with pivot points to assist in the depth control or may operate independent of and without impeding depth control.

RELATED APPLICATIONS

This patent application is a continuation application claiming priorityto U.S. patent application Ser. No. 16/148,910, filed Oct. 1, 2018,which is a continuation in part application claiming priority to U.S.patent application Ser. No. 13/686,461 which was filed Nov. 27, 2012,which claims priority to U.S. Provisional Patent Application No.61/565,278 which was filed Nov. 30, 2011 and is hereby incorporatedherein by this reference.

FIELD OF THE INVENTION

The present invention relates to systems and methods for millingasphalt. More specifically, the present invention relates to attachablesystems and methods that improve milling by providing steeringcapability while maintaining depth control for a milling device.

BACKGROUND OF THE INVENTION

Portable asphalt milling attachments historically comprise two principalfeatures. They have a way to control the depth that the millingattachment device cuts. They also have a way to facilitate the changingof bits mounted to a cutting wheel of the milling attachment device.However, such devices are quite heavy and can prove very difficult tosteer and keep on line, particularly when the host vehicle is small orhas difficulty moving very heavy objects.

BRIEF SUMMARY OF THE INVENTION

The present invention has been developed in response to the presentstate of the art, and in particular, in response to the problems andneeds in the art that have not yet been fully solved by currentlyavailable asphalt milling/trenching attachments.

This disclosure provides steering capability that operates independentof or can be integrated with depth control and will not interfere withbit access.

The front of the machine has one or more steerable wheels that arecontrolled hydraulically, electrically, pneumatically, or by using anyother suitable drive. The wheel or wheels may be of any suitable type,including caster-type wheels, and may be raised or lowered to maintaindesired depth control in the milling/trenching process. In certainembodiments, the steerable wheels are disposed forward of the millingassembly such that they will not impede bit access for repair and/orreplacement.

Asphalt milling devices are quite heavy and some are self-propelled. Theself-propelled asphalt milling devices are steerable, but are extremelyexpensive and have limitations. Asphalt milling attachments can beattached to and maneuvered by a host vehicle, but heretofore the hostvehicle provides the steering. Because asphalt milling attachments arequite heavy, smaller host vehicles or host vehicles that have difficultymoving very heavy objects have difficulty steering when a millingattachment is attached. The attachment embodiments disclosed hereinfacilitate maneuverability by providing a steering mechanism for theattachment. The asphalt milling attachments of the present disclosurecould use a bucket slot in the rear of the asphalt milling attachment toallow a host vehicle to connect to it. Alternatively, other knownquick-connects (JRB style, skid steer or balderson style) could be used.Host vehicles for the asphalt milling attachment could include backhoes, loaders, excavators, track hoes, skid steers and the like.However, without the steering capability provided in the presentdisclosure, steering the asphalt milling attachment or maintaining adesired line and milling depth can prove to be very difficult for anoperator of the device, particularly if the host vehicle is a smallervehicle. The present invention is much more versatile than known asphaltmilling devices because it provides steering capability for the asphaltmilling attachment that can be attached to and used by broader range ofhost vehicles. In one embodiment, the wheel is a caster wheel that canbe locked into a particular orientation (such as directly forward) orunlocked so that the operator can steer the device right or left. Insome embodiments, the steering capability is independent of the depthcontrol, and does not interfere with depth control. In other embodimentsthe steering is integrated with the depth control such as when the wheelis also connected to a framework that can be raised or lowered to assistin controlling the depth of the milling performed by the device.

With the steerable wheel system in use, the intended use of the asphaltmilling device could be to cut asphalt, concrete or any other roadconstruction/parking lot material. The milling device could also be usedfor soil stabilization. It could be used for full depth reclamation ofroads. These and other features will become more fully apparent from thefollowing description, or may be learned by the practice of thesteerable wheel system as set forth hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In order that the manner in which the above-recited and other featuresand advantages of the invention are obtained will be readily understood,a more particular description of exemplary embodiments of the invention,briefly described above, will be rendered by reference to specificembodiments thereof which are illustrated in the appended drawings.Understanding that these drawings depict only typical embodiments of theinvention and are not therefore to be considered to be limiting of itsscope, the invention will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1 is an elevation view of an asphalt milling device with a steeringmechanism and showing a host vehicle in outline to illustrate oneexemplary method for connecting the host vehicle to the asphalt millingdevice;

FIG. 2 is a perspective view of an exemplary asphalt milling device witha steering mechanism;

FIG. 3 is a perspective frontal view of an asphalt milling deviceshowing various components of an exemplary steering mechanism;

FIG. 4 is a perspective right side view of the steering mechanism forthe asphalt milling device;

FIG. 5 is a perspective left side view of the steering mechanism for theasphalt milling device;

FIG. 6 is a perspective view of an alternative two-wheel embodiment of asteering mechanism for an alternate asphalt milling device showing thewheels in a forward mode;

FIG. 7 is a perspective side view of the alternative two-wheelembodiment of the steering mechanism for the alternate asphalt millingdevice showing the wheels in a side mode;

FIG. 8 is an elevation view of an asphalt milling device with agroundsman guiding a steering mechanism and showing a host vehicle inoutline to illustrate one exemplary method for connecting the hostvehicle to the asphalt milling device; and

FIG. 9 is an elevation view of an asphalt milling device with agroundsman guiding a steering mechanism along a guidance system andshowing a host vehicle in outline to illustrate one exemplary method forconnecting the host vehicle to the asphalt milling device.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the invention will be best understood byreference to the drawings, wherein like parts are designated by likenumerals throughout. It will be readily understood that the componentsof steerable asphalt milling devices, as generally described andillustrated in the figures herein, could be arranged and designed in awide variety of different configurations. Thus, the following moredetailed description of the embodiments of the present disclosure, asrepresented in the figures, is not intended to limit the scope of theinvention, as claimed, but is merely representative of exemplaryembodiments of the invention.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. While the various aspects of theembodiments are presented in drawings, the drawings are not necessarilydrawn to scale unless specifically indicated.

In this application, the phrases “connected to”, “coupled to”, and “incommunication with” refer to any form of interaction between two or moreentities, including mechanical, hydraulic, electrical, magnetic,electromagnetic, and pneumatic interactions.

The phrases “attached to”, “secured to”, and “mounted to” refer to aform o f mechanical coupling that restricts relative translation orrotation between the attached, secured, or mounted object, respectively.

The term “pivoting” refers to items that rotate about an axis. A“pivoting engagement” is an engagement between two or more items indirect contact, with one or more of the items being capable of pivotingabout an axis common to each of the items.

FIG. 1 is an elevation side view of an embodiment of an asphalt millingdevice 10 with a steering mechanism 12 and is shown as attached to anexemplary host vehicle 50. This embodiment shows that the asphaltmilling device 10 is an attachment that is connected to a bucket-type ofhost vehicle 50 that can be used to drive and steer the device 10. Thehost vehicle 50 has a bucket 52 that engages a bucket slot 13 on theasphalt milling device 10. Alternatively, known quick-connects (JRBstyle, skid steer or balderson style) can be used to connect the hostvehicle 50 to the asphalt milling device 10. Because the asphalt millingdevice 10 has a steering mechanism, various types of host vehicles 50can be used to connect to and steer the steerable asphalt milling device10, including back hoes, loaders, excavators, track hoes, skid steersand the like.

FIG. 2 is a perspective view of an exemplary asphalt milling device 10with the steering mechanism 12 ready for connection to the host vehicle50. The steering mechanism 12 comprises a wheel 14 pivotally mounted toa support bar 16 via a substantially vertically disposed pivot shaft 18,a pair of cooperating, steering actuators 20, a pair of stationarybrackets 22, a rotating bracket 24, and a hydraulic drive (not shown).In FIG. 2, the wheel 14 is a caster-type wheel securely connected to thepivot shaft 18 so that when the pivot shaft 18 rotates, the wheel 14also rotates. It should be understood that other types of wheels can beused, but the caster-type wheel 14, as shown in FIGS. 2 and 3, isparticularly suitable for the intended use.

The pivot shaft 18 is carried in a shaft opening in the support bar 16and extends above the support bar 16 so that the rotating bracket 24 canbe attached to the pivot shaft 18. The rotating bracket 24 comprises acollar 28 and laterally extending ears 30 (the reference numerals 28, 30are not shown in FIG. 2 so not to obscure other features of the device;however, collar 28 and ears 30 may be similar to what is shown in FIG.3). The collar 28 fits snug about the pivot shaft 18 and can be securedto the pivot shaft 18 by any suitable means, such as by screw, bolt,key, set screw, weld, or the like. Ears 30 provide a location forpivotally attaching the cooperating steering actuators 20. Each of thestationary brackets 22 is secured to the support bar 16 and spaced toprovide locations for pivotally attaching the cooperating steeringactuators 20. One end of each steering actuator 20 is pivotally attachedto a stationary bracket 22 while the other end is pivotally attached toears 30 of the rotating bracket 24, so that distance between the twostationary brackets 22 is covered by the ears 30 and steering actuators20, with the ears 30 being disposed between the two steering actuators.In this manner, as one of the steering pistons 20 contracts, the othersteering piston 20 extends, thereby causing the ears 30 to move to theright or left and rotating the pivot shaft 18 and wheel 14 accordingly.A hydraulic drive (not shown in FIG. 2) is connected to the steeringpistons 20 via hydraulic hoses and fittings 32 (not shown in FIG. 2). Byregulating the extension and contraction of the steering actuators 20via the delivery of hydraulic fluid through the hoses and fittings 32,the user can steer the wheel 14 in a desired direction. Although ahydraulic drive is disclosed, it should be understood that other typesof drives may suitably rotate the pivot shaft 18, thereby steering thewheel 14.

FIG. 3 is a perspective frontal view of an exemplary embodiment of anexemplary asphalt milling device 10. The steering mechanism 12 comprisesa wheel 14 pivotally mounted to a support bar 16 via a substantiallyvertically disposed pivot shaft 18, a pair of cooperating, steeringactuators 20, a pair of stationary brackets 22, a rotating bracket 24,and a hydraulic drive (not shown). In FIG. 3, the wheel 14 is acaster-type wheel securely connected to the pivot shaft 18 so that whenthe pivot shaft 18 rotates, the wheel 14 also rotates. It should beunderstood that other types of wheels can be used, but the caster-typewheel 14 is particularly suitable for the intended use.

The pivot shaft 18 is carried in a shaft opening in the support bar 16and extends above the support bar 16 so that the rotating bracket 24 canbe attached to the pivot shaft 18. The rotating bracket 24 comprises acollar 28 and laterally extending ears 30. The collar 28 fits snug aboutthe pivot shaft 18 and can be secured to the pivot shaft 18 by anysuitable means, such as by screw, bolt, key, set screw, weld, or thelike. Ears 30 provide a location for pivotally attaching the cooperatingsteering actuators 20. Each of the stationary brackets 22 is secured tothe support bar 16 and spaced to provide locations for pivotallyattaching the cooperating steering actuators 20. One end of eachsteering actuator 20 is pivotally attached to a stationary bracket 22while the other end is pivotally attached to ears 30 of the rotatingbracket 24, so that distance between the two stationary brackets 22 iscovered by the ears 30 and steering actuators 20, with the ears 30 beingdisposed between the two steering actuators. In this manner, as one ofthe steering actuators 20 contracts, the other steering actuator 20extends, thereby causing the ears 30 to move to the right or left androtating the pivot shaft 18 and wheel 14 accordingly. As shown in FIG.3, the steering actuators 20 are hydraulic pistons. However, it iscontemplated that the steering actuators 20 may be electrical,pneumatic, or may be powered by any other suitable drive withoutdeparting from the concepts of the invention contemplated. For clarityin the remaining description, the steering actuators 20 are hydraulicpistons, as shown.

The hydraulic drive (not shown in FIG. 3) is connected to the steeringactuators 20 via hydraulic hoses and fittings 32. By regulating theextension and contraction of the steering actuators 20 via the deliveryof hydraulic fluid through the hoses and fittings 32, the user can steerthe wheel 14 in a desired direction.

FIGS. 4 and 5 are perspective right side and left side views,respectively, of the steering mechanism 12, showing a height-adjustmentmechanism 34 for the steering mechanism 12. Because the asphalt millingdevice 10 can mill to various depths, the height of the wheel 14 of thesteering mechanism 12 is also adjustable to assist in maintaining depthcontrol. In some embodiments, the wheel 14 can be raised and loweredusing a pivoting parallelogrammatic structure, generally designed as 36,and comprising four pivot points 38 a, 38 b, 38 c, and 38 d. Betweenpivot points 38 a and 38 c, a height-adjusting strut such as aheight-adjusting hydraulic piston 40 is provided. By extending andcontracting the length of the height-adjusting strut (e.g., a hydraulicpiston 40), the configuration of the parallelogrammatic structure 36will change and the support bar 16 and wheel 14 can be raised andlowered to achieve a desired milling depth or to lift the front of theasphalt milling device 10 to clear a zero milling depth. Although ahydraulic piston 40 is shown, it should be understood that any type ofheight-adjusting strut that effectively alters its operating length withrespect to the parallelogrammatic structure 36 may be used. Also, itshould be understood by those skilled in the art that theheight-adjusting strut can be connected to the parallelogrammaticstructure 36 between points on the structure other than pivot points 38a and 38 c, so long as the strut can still change the configuration ofthe structure 36 to raise and lower the support bar 16. By way ofexample of struts other than a hydraulic piston 40, the strut can belength-adjustable or telescoping linkage that is attached betweenadjacent sides of the parallelogrammatic structure 36.

As shown in both FIGS. 4 and 5, a support arm 41 is connected to thesupport bar 16 and a portion of the support arm 41 (designated as 43)forms one of the sides of the parallelogrammatic structure 36.

FIG. 4 also shows the hydraulic hoses and fittings 32 extending from thesteering mechanism 12. Similarly, the height-adjusting hydraulic piston40 has hoses and fittings 42. These hoses 32, 42 are connected to thehydraulic drive (not shown) which is controlled by control means knownin the industry. However, it should be understood that more than onehydraulic drive (or any other type of suitable drive) may be used todrive the various driven components described herein.

FIGS. 6 and 7 are illustrations of an alternative embodiment, using atwo-wheel configuration on an asphalt milling device 10, showing adifferent steering mechanism 12 and height control. With thisalternative embodiment, each wheel 14 is mounted to an arm 26 thatextends from the support bar 16. The pivot shaft 18 is encased within acylinder 44 on the end of the arm 26. The direction of each wheel 14 canbe controlled by independent synchronized actuator steering or can belocked, using a locking mechanism 45, into a particular directionmanually (see e.g., the array of pin holes 46 and the locking pin hole48 into which a locking pin (not shown) can be inserted). Independentsynchronized actuator steering can be controlled hydraulically(hydraulic fittings 32 are shown in FIG. 6) to rotate the wheels 14 forsteering. When a single, constant direction is desired, the lockingmechanism 45 can be locked into a particular direction. Though thesteering mechanism 12 differs from the single wheel embodiment describedabove, one skilled in the art can readily practice the two-wheeledembodiment based on the above disclosures and the figures shown.

The alternative embodiment of a two-wheel configuration for the asphaltmilling device 10 of FIGS. 6 and 7 illustrates an embodiment where anouter frame 54 is rigid and is supported by the wheels 14 and an innerframe 56 that can hydraulically lift or lower the rotating cutting head58 into place for milling at depths ranging from zero depth to fulldepth. The inner frame 56 is lifted/lowered so that the cutting head 58is disposed in the desired cutting position by hydraulic struts 60 whilethe outer frame 54 maintains its disposition supported by the wheels 14and the host vehicle 50.

Additionally, the arms 26 may pivot about their connections to thesupport arm 16 so that the wheels 14 can swing from a forward mode (FIG.6) to a side mode (FIG. 7). When in the side mode, the cutter head 58can advance much closer to a wall, an obstacle, a barrier, or the like,at the front of the asphalt milling device 10, while maintainingsteering capability.

Although the exact configuration of the hydraulic drive together withthe hoses and fittings, and the controls for regulating the hydraulicpower have not specifically been shown, one skilled in the art, armedwith the disclosure provided herein can configure the hydraulics toprovide both steering and height-adjustment by locating needed controlsin the host vehicle 50.

FIGS. 8-9 show a perspective view of another alternative asphalt millingdevice 10 further comprising a groundsman operator operating a guidancesystem 62. In certain embodiment the guidance mechanism comprises alight source 64 and a target. In certain embodiments the guidance systemlight source comprises a photoelectric sensor which emits a beam ofvisible or infrared light, including a laser beam, towards a target,such as a reflector, which when properly aligned reflects back a portionof the light beam to the sensor on the steering mechanism. In someembodiments the beam projector is mounted on the front of the steeringmechanism. In some embodiments the beam projector is mounted above thesteering mechanism on an extension.

A target is also provided. In embodiments involving shorter distance thetarget comprises a reflective surface so as to reflect an aligned lightbeam sent from the light source back to the photoelectric sensor. Incertain embodiments involving longer distances the target is a sensorwhich receives an aligned light beam sent from the light source andtransmit a signal via wires or wirelessly, that the beam is aligned. Incertain embodiments the target comprises adjustable blinders whichcreate an aperture between the light source and the target to ensure thedesired milling depth has been achieved. In certain embodiments theblinder is used to set a vertical high limit. In some embodiments thelower limit is functionally set by the maximum milling depth set by thephysical limitations of the milling attachment.

Some embodiments comprise a light beam projected on a sensing targetwherein the target senses whether the position of the light beam iswithin pre-set tolerances. In some embodiments the guidance systemprovides an alert, such as a sound, a light or vibration to alert theoperator the beam is out of alignment. In some embodiments the guidancesystem notifies the operator what corrective action required to realignthe steering mechanism with the predetermined course. In someembodiments the steering mechanism become misaligned and require asteering correction. In some embodiments when the light beam is out ofalignment the operator manually determines the cause of the misalignmentand manually guides the steering mechanism into alignment. In someembodiments the guidance system may sense the beam moved off a specificside of the target (e.g. right) and thus indicate a steering correction(e.g. to the left) is required to regain alignment, or vice versa.

In some embodiments the guidance system is used to confirm the depth ofthe milling. In some embodiments the sensor may sense the beam movedvertically out of alignment and indicate the vertical misalignment to anoperator. In some embodiments the vertical misalignment may be causedthe material being milled. In the milling process the rotating cuttinghead may encounter materials of different hardness, and depending on thespeed the rotating cutting head may pass over the material withoutproperly milling or pulverizing the material. In some instances theprogress of the host machine and milling attachment are stopped andpossibly even reversed to permit the rotating cutting head to operateuntil the milling or pulverization is complete. In some embodiments thevertical misalignment may prompt the operator to put more pressure onthe rotating cutting head. In some embodiments the increased pressure isaccomplished by the host vehicle lowering the boom connected to themilling attachment, thus placing more of the host vehicle's weight onthe milling attachment and forcing the rotating cutting into thematerial. The additional downward force will drive the cutting head 58into the material being milled. In certain embodiments the idealdownward force on the milling attachment is created when the hostvehicle's front wheels are almost off the ground.

FIG. 9 shows that in some embodiments the guidance system comprises alight beam 68, such as a laser emitted from a light source 66 alignedalong the side of the milling path and a ring 70 a and 70 b, or a seriesof rings extending from the side of the milling attachment aligned sothat the laser is directed through the center of the rings. In someembodiments a groundsman observes the alignment of the laser through thering, and adjusts height or direction of the milling attachment asnecessary to maintain the alignment of the milling attachment on themilling path. In some embodiments the guidance system comprises one orboth of the guidance systems.

In some embodiments instead or lowering a boom to increase pressure theheight-adjustment mechanism 34 can be adjusted completely mill theground and realign the steering mechanism. Because the asphalt millingdevice 10 can mill to various depths, the height of the wheel 14 of thesteering mechanism 12 is also adjustable to assist in maintaining depthcontrol. In some embodiments, the wheel 14 can be raised and loweredusing a pivoting parallelogrammatic structure, generally designed as 36,and comprising four pivot points 38 a, 38 b, 38 c, and 38 d. Betweenpivot points 38 a and 38 c, a height-adjusting strut such as aheight-adjusting hydraulic piston 40 is provided. By extending andcontracting the length of the height-adjusting strut (e.g., a hydraulicpiston 40), the configuration of the parallelogrammatic structure 36will change and the support bar 16 and wheel 14 can be raised andlowered to achieve a desired milling depth or to lift the front of theasphalt milling device 10 to realign the steering mechanism. The raisingand lowering of the height-adjustment mechanism in response to sensedmisalignment can be used to compensate for depressions in the ground'ssurface contours.

In some embodiments the steering guidance system further comprisesremote steering member. In some embodiments the remote steering membercomprises a relay remote control unit, configured to allow an operatorto correct misalignments. In certain embodiments this relay remotecomprises a notification mechanism which notifies the operator when thesteering mechanism is misaligned. In some embodiments the relay remotecomprises steering controls to direct the steering mechanism and correctfor horizontal misalignment. In certain embodiments the relay remotecomprises controls for the height-adjustment mechanism 34. In someembodiments the relay remote is used by the operator of the host vehicleto adjust the downward pressure on the boom. In some embodiments therelay remote is wirelessly connected to the guidance system. In someembodiments the relay remote is connected to the guidance system by awire wherein the operator is a groundsman walking on the ground next tothe steering mechanism to observe the position of the steering mechanismas it moves. In some embodiments the steering guidance system isconfigured in the host vehicle cab to allow the host vehicle operator tooperate both the host vehicle and the steering mechanism, as well as themilling depth.

In some embodiments a steering mechanism control, along with a visualobservation system is configured away from the front of the millingattachment, such as in the host vehicle's cab, to obviate the need for agroundsman. In some embodiments the visual observation system comprisesone or more cameras positioned to provide a view of the millingattachment's direction. In some embodiments one or more observationmembers, such as cameras, is positioned to provide a view of the millingattachment's milling depth. In some embodiments one or more cameras ispositioned to provide a view of the guidance system to visually indicatewhen the milling attachment is the correctly aligned. In someembodiments one or more visual, such as a LCD screen, LED screen, ELDscreen, or phosphorous screen, displays the alignment of the millingattachment with the guidance system.

The present invention may be embodied in other specific forms withoutdeparting from its structures, methods, or other essentialcharacteristics as broadly described herein and claimed hereinafter. Thedescribed embodiments are to be considered in all respects only asillustrative, and not restrictive. The scope of the invention is,therefore, indicated by the appended claims, rather than by theforegoing description. All changes that come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

The invention claimed is:
 1. A steering mechanism to provide steeringcapability for both a host vehicle and for a milling attachment separatefrom, but connectable to the host vehicle operated by an operator, thehost vehicle providing propelling force to the milling attachment, themilling attachment having an outer frame, a height-adjustable innerframe, and a rotating cutting head fixed to the inner frame so that thecutting depth of the rotating cutting head depends on the adjustedheight of the inner frame relative to the outer frame, the steeringmechanism, comprising: an attachment mechanism configured to connect amilling attachment to a host vehicle; a first wheel mounted to a firstpivot shaft; a second wheel mounted to a second pivot shaft, the outerframe being supported by the first wheel, the second wheel, and the hostvehicle; a support bar disposed across the front of the millingattachment forward of the rotating cutting head and connected to theouter frame, the support bar for receiving a first arm in pivotingengagement and a second arm in pivoting engagement, the first armreceiving the first pivot shaft in pivoting engagement and the secondarm receiving the second pivot shaft in pivoting engagement, wherein thefirst arm and the second arm are each pivotally movable from a forwardmode to a side mode enabling the front of the milling attachment toadvance proximate an obstacle while maintaining steering capability; afirst steering actuator connected to and providing powered rotary motionto the first pivot shaft and the first wheel; a second steering actuatorconnected to and providing powered rotary motion to the second pivotshaft and the second wheel; a guidance system configured to indicate thealignment of the steering mechanism in relation to a predetermined path;and milling attachment steering controls positionable for access andactuation by the operator within the host vehicle to steer the millingattachment and the host vehicle, the steering controls being connectedto the first steering actuator and second steering actuator of thesteering mechanism allowing an operator to control steering of both thehost vehicle and the milling attachment by activating the first steeringactuator and the second steering actuator.
 2. The steering mechanism ofclaim 1 further comprising a light source mounted on the millingattachment and directed to a target configured to inform the operatorthe alignment of the milling attachment with a milling path.
 3. Theguidance system of claim 2 further comprising a target mounted on themilling attachment and configured to show the alignment of the targetwith a light source aligned with a predetermined milling path.